Low-fat diets lower men’s testosterone levels by 10-15% , according to a new study conducted at the University of Worcester and published in the Journal of Steroid Biochemistry and Molecular Biology .
Low testosterone levels are linked to an increased risk of heart disease, diabetes, and Alzheimer’s disease. Healthy testosterone levels are also key to men’s athletic performance, mental health, and sexual health.
Hypogonadism since 1970
The study was a systematic review and meta-analysis, combining the results of six well-controlled studies with a total of 206 participants. These studies first put the men on a diet high in fat (40% fat) and then transferred them to a diet low in fat (20% fat) and found that their testosterone levels decreased by 10-15% in average. Particularly bad were the low-fat vegetarian diets that led to a decrease in testosterone of up to 26% .
A high intake of monounsaturated fats found in olive oil, avocados, and walnuts can increase testosterone production. However, omega 6 polyunsaturated fats, which are predominantly found in vegetable oils, can impair the ability of cells to produce testosterone . This is because highly unsaturated fats, such as polyunsaturated ones, are more prone to oxidation, which causes cell damage.
Since the 1970s, there has been a decline in men’s average testosterone levels and rates of hypogonadism (medically low testosterone) have increased.